The present invention relates to a fuel-driven setting tool for driving fastener elements such as nails, bolts, pins and the like into a substrate. The setting tool has a setting piston guided in a piston guide, is displaceable using the combustion energy of a propellant, and has a voltage source for supplying electrical consumers on the setting tool. Such setting tools can be driven using gaseous, vaporizable fluids or solid fuels. A setting piston is driven, in the fuel-driven setting tools, in the setting operation by combustion gases. The fastening elements can be driven into a substrate by the setting piston. Thermal energy is produced, in the setting operation with the kinetic energy of the moving setting piston, which, if required, is diverted over a cooling system, such as cooling ribs or fins etc. to the environment.
Setting tools of this type generally comprise electronic components such as electronically controlled valves, ignition systems, fans, sensors, etc. These components and their control systems must be supplied with electrical energy such that independence of electrical mains is desirable.
U.S. Pat. No. 4,403,722 discloses a gas-driven setting tool, in which the air and fuel gas mixture in the combustion chamber is homogenized by an electrically driven fan prior to ignition. A NiCd storage battery provides electrical power to the fan drive and its control system.
The drawback is that the NiCd storage battery must be recharged by an external energy source. The storage batteries must be removed from the setting tool, which is relatively inconvenient for the user.
U.S. Pat. No. 6,123,241 discloses a gas driven setting tool, wherein an extensive electronic control system controls and/or monitors different electronic systems. Different sensors such as temperature, pressure and work surface temperature sensors, an electronic ignition and an electronically driven fan are arranged on the setting tool. Two electrical power sources are required for supplying power to this setting tool. An alkaline battery supplies the microprocessor, which is the nucleus of the controls, with electrical energy and a lead-acid battery is the main battery. In this setting tool, external recharging of the lead-acid battery is required.
A fuel-driven setting tool is known from DE 40 32 303 A1, in which permanent magnets are arranged on one wall of the combustion chamber facing the piston for temporarily holding the piston.